THE PALEOCENE and MODERN TERMITES

by Charles Weber MS

Turtles survived without teeth into the Paleocene. The economy inherent in a skeleton that was both armor and support may
be the reason. Turtles, lizards, snakes and crocodiles survived into the Paleocene. All but the turtles were
carnivorous and therefore these non turtles would not be as effected by a phosphorus shortage as the
herbivores. Non of those carnivores lost teeth. Of course those small carnivorous dinosaurs we call birds survived also. Their loss of teeth was probably because of ingestion of mating flight termites of the soil borne type with the iron oxides in their gut that binds phosphorus. For a critical discussion of various end of the Cretaceous extinction hypotheses, see this site.

Savanna herbivorous mammals had small jaws and teeth. The horses which became apparent later in the Paleocene had a small fragile head with a set of small, short crowned teeth
devoid of both enamel and cement. The increased erosion by the end of the Paleocene [Foreman] no doubt was caused by the baring of soil by termites and contributed to this loss of fertility. The radiation of small mammals was well underway before the Paleocene in North America [Archibald p259]. Indeed,all mammals were very small from upper Triassic until upper Cretaceous.
There was a gradual loss of upper Cretaceous mammals and all dinosaurs there [Archibald p xii], which argues against a sudden catastrophe from the meteor impact in Mexico and the impact in Iowa [Anderson RR] as the only cause. Indeed, the extinctions were probably not exactly at the same time as the Mexican impact. Also see this site for good graphs and discussion. There were very few large terrestrial animals in Montana, which is thought to have had a climate like northern Florida [Retallack 1994], which climate warmth was almost certainly from the action of termites in baring the soil.

The savanna horses and camels in Africa and Eurasia as well as lands connected to them showed a slow recovery across the Tertiary. These are the areas where ant genera became effective on the savannas. Lobopolata distinguenda (McCook 1909), Euponera sennaerensis, Termitoponocommutala, and Opthalmopona berthondi form fairly large colonies and are effective (Wheeler 1937). Megaponera foetens is one of the most effective species (Hegh 1922), sometimes fielding as many as a thousand ants in a raid. Opthalmopone ilgii of southern Abyssinia is sufficiently organized that it sends back some of its members from an assembly point after a raid to carry back laggards bodily if necessary (Wheeler 1913, p240). The Dorylenes are all rain forest and none extend out into the savanna.

It has been suggested that a huge meteor or meteors struck the earth and caused the large dinosaurs to become extinct. This is very plausible. It was not necessary for the meteor to kill the large herbivores. If only the few large predators which inhabited the
reduced patches of fertile delta rain forest which I envision became extinct, the herbivores would rapidly follow, since these
predators are the main advantage of large size and the savannas had become almost as much a barrier to migration as an ocean. It is difficult to envision less than ten square kilometers supporting the prey for a pair of Tyranosaurs, let alone a breeding population of Tyranosaurs. However it is still necessary to explain why vertebrates took so long to recover their size during the Paleocene [Smith FA]. We have seen body size and even separate organs change drastically in only a few thousand years in dogs, food plants, and decorative plants. Large animals that reach islands decline rapidly in size. Guppies can evolve a different size with changes in predation in less than ten years (Resnick). Why then were many millions of years and worldwide populations not sufficient in the Paleocene? I suspect it had to do with soil phosphorus fertility. Analyses of ancient soils could prove interesting.

Immediately at the Cretaceous-Paleocene border coal began to appear in North America [Archibald p 249]. Perhaps this may have been a response to arrival of Dorylene ants from South America into the rain forests.

OCEANS

It may be that the ocean was affected by these events also. In the early Cretaceous it may have been that most of the phosphorus
that came down to the ocean in rivers was in the form of organic matter which would largely enter the ocean economy. The high
phosphorous content of some early and mid Cretaceous greensands would reinforce this contention. However, when the phosphorus began
to come down in the form of iron and aluminum oxide sediments, not only did it settle out without entering the food chain, but
these sediments even adsorbed a little of the inorganic phosphorus already there. This could conceivably explain the decline of some
of the ocean life toward at the end of the Cretaceous such as the large reptilian vertebrates. If phosphorus was the cause of
loss of ocean productivity, it lasted at least half a million years into the Paleocene (Zachos, et al).

ISLAND ECOLOGY
and PACIFIC OCEAN ISLANDS

It appears to me that many Pacific Ocean islands recently resembled the world as it existed before the Permian so far as soils and their fauna are concerned. Primitive collembola, cockroaches, snails, introduced earthworms, gecko lizards, and rats and the like were characteristic. The soils were high in organic matter (estimated) and covered with debris and rotting logs. The only ants were ponerines. All this was in Bora-Bora (Cheesman, 1927). Soil borne termites were nonexistent. According to Freeman, on the Gilberts and Marshall islands humus piled up almost ten feet deep in the interiors (Freeman p277). Previously in Hawaiian humid regions the
organic matter made up to ten to thirty five per cent by volume of the top soil. The soil's natural fertility is moderately high
(Freeman, 1951), but it is low in calcium (Orr, 1929). Such situations are reminiscent of the Carboniferous. If a soil contains 15% of organic matter or more other factors cease to count for much. The distinction between sands, silts and clays are often considerably diminished (Russell, 1932)

CUBA

Cuba has termites with a South American affinity, most capable of being spread on floating logs. Neotermes is present. The termites provide a situation similar to as I envision it in early Cretaceous. Heterotermes, a primitive soil borne genus of the Rhinotermitidae family related to Reticulitermes, is present. Anoplotermes of the Amitermitinae are present but I do not know of its effect on soils. Ponerine, Dorylene, (Creighton, 1950) and leaf cutter ants are present in the Antilles, but their effect on the environment is unknown to me. The soils are very fertile and support a large human and animal population. Endemic vertebrates were previously only
small rodents. Soils are well drained and in some areas are as fertile at depth as they are at the surface. It has been suggested that the vesicular structure of ancient laterites was due to the tunneling of termites (Prescott, 1952). Laterites have been discovered as far back as the upper part of lower Cretaceous (Wahlstrom, 1949). If this structure is due to termites, I suspect that it would be from the activity of Heterotermes. One would think that Cuba might be a good place to look for evidence that Prescott had figured out vesicular structure of laterites correctly.

MADAGASCAR

I would be inclined to place Madagascar to resemble the Asian soil conditions as I view them about the middle to upper Cretaceous. However, Mastotermitidae is absent and Amitermitinae is poorly represented. Its termite population consists of four species of Kalotermes, two of Cryptotermes, two of Procryptotermes, six of Neotermes, one of Coptotermes, three of Microcerotermes, five of Microtermes,
and eight of Nasutiform termites. Heterotermes is displaced by Psammotermes, an African savanna termite. Emerson, A.E., has an undescribed Amitermes specimen. The plains are covered with great numbers of mounds in some places (Sjostedt, 1914)
(Holmgren, 1909) which include Eutermes, a nasuti. Madagascar's termites are probably chance over water immigrants with most diversity in the dry south [Paulian], probably primarily from dry adjacent regions of Africa. I do not know if any of these are effective humus eaters. Madagascar's Ponerine ants make small colonies of timid, blind, poorly organized colonies (Forel 1921, p159) (Wheeler 1913). There are no Dorylenes.

There are no Echidna, Edentata, or Pangolan anteaters.

The soil is generally infertile. The plateau savannas are of large extent and consist of poor latosols (a generic term which signifies
soils high in iron and aluminum oxides and low in silica, now called ultisols or oxisols). I do not know if they have been correctly categorized with respect to silica. Sibree comments on the extreme scarcity of organic matter in the soil
(Sibree, 1880). Release of phosphates bound to the soil depends to a considerable extent upon being replaced by organic ions
released from decomposing organic matter, so what phosphorus is in the soil must be difficult for the plants to acquire. Though the
soils are derived from a variety of materials, the subsoil is very poorly drained. This is more than likely related to its low organic
content, which in turn is undoubtedly the result of the decreased production and the decreased incorporation into topsoil caused by
termites (Hegh, 1922 p655). Alluvium of the coast plains and lakes is fertile and black in color. Tertiary sediments support an
arborescent flora. (Enc, Brit., Vol. 14, p600).

The rain forest trees have such forms as ebony and similar hardwoods, very many tree ferns, pandans, bamboos, and very many palms, unlike a complete absence of pandans and palms in non swampy Africa or tree ferns outside of montane Africa. The trees are all shrub like, with narrow stems. The savannas are shrub savannas with little grass (Grubb), perhaps because of the absence of grazing animals. The narrow stems in the rain forest may be resulting from Coptotermes presence. There are no Sequoia. The forested area is confined to
two narrow bands within 50 miles of the east coast and one narrow band on the western side. There are many cycads on the plains {savannas?} (Sibree, 1880). This poor forestation is in spite of adequate rain from the Indian ocean. Even in the southwest desert the rainfall is 20
inches.

The endemic vertebrates are moderate in size. Birds rivaling a New Zealand Moa in size, Hippopatami somewhat smaller than those
of the Nile, species of swine, a root eating river hog, a slender legged Zebu ox, a lemur about the size of a man, and giant tortoises are found on the fossil record, presumably reared on the fertile alluvium. Many are believed to be contemporaneous with the first men. Man high stands of grass in the interior support many locusts, which in turn support many birds and an unusually large number of hawks. The marshes also support many birds.

I would be inclined to tentatively assign the alluvium forest to Paleocene or Eocene and the savanna to upper early Cretaceous, just before the
demise of the Pterosaurs. If the bird population is indicative there must have been a large Pterosaur and/or bird population in the mid Cretaceous on the World’s savannas, although small dinosaurs are also plausible. Perhaps the rain forest is similar to upper Cretaceous.

I know of no area in the present world which is quite like the end of the Cretaceous or early Paleocene on the savanna. Perhaps some parts of Australian savannas come close. However, all
the genera extant then have similar species still with us some where in the world, so we could easily create such an island or enclave in order to find out
what it was like.

AUSTRALIA

Northern Australian savannas appear to resemble in many respects conditions that I have proposed for the Eocene. There are many species of Amitermitinae (now merged with Termitinae). In some places they dominate the savanna landscape with many large above ground nests. Other types are well represented. Drepanotermes and Tumulitermes are the grass harvesters in Australia [Andersen A]. Insects are the chief herbivores on the savannas. It is the only continent with a species of Mastotermitidae. In nature, Mastotermes of that family is not very numerous nor are the colonies large. Its diet is very varied. It will eat saplings [Hicken], introduced plants, damage ivory and
leather, and eat wood and debris. It becomes a major agricultural pest, to the extent that vegetable farming has been virtually
abandoned in Northern Australia (Hill, 1942) wherever this termite is numerous, which it is outside of the rain forest or bauxitic soils [Bratton, p285]. It has developed the ability to bore up into a tree and ring bark it such that it dies and becomes the center of a colony. It attacks mainly saplings [Hicken]. Some of the Australian Coptotermes build mounds, unlike in other regions. Coptotermes are the only genus outside of the Termitidae to build above ground nests [Noirot, p81]. Therefore it is possible that Coptotermes can convert the vegetation on even some poorly drained soil into savannas, or close to it. Half the eucalypt trees in the west are badly damaged by Porotermes adamsoni [Hicken]

The Myrmecinae are restricted to Australia and New Caledonia [Britton]. The Ponerine ants are the dominant termite check in Australia (Haskins, 1939)(Wheeler, 1910). Myrmecia or bulldog ants are the most successful. They make fairly large colonies of two hundred to a thousand very aggressive ants armed with stings. Their large size [2- 2.5 cm.] would seem to preclude entering a termite nest. They are confined to the northern coast with the exception of one species which extends out onto the savanna (Wheeler, 1910). The Ponerine genus Amblyopone is also present (Forel, 1921). Australian Ponerines hunt singly or in small groups (Haskins, 1939), so can not be putting much pressure on termites. Two Dorylene species of Aenictus genera from Asia are present. They may make the rain forest similar to
conditions as they existed in upper Eocene in Eurasia. It is possible that Aenictus may give termites a net advantage by preying on ants preferentially, although I have no definitive evidence of this.

The Echidna anteater, a small egg laying mammal (Tachyglossus aculeatus), another marsupial anteater with burrowing forelegs (Myrmecobious fasciatus) a bandicoot with digging forefeet (Paramelidae0, and Leptodactylid myobatrachus gouldi which burrows are present, but I don't know their ranges or effect on termites.

The monsoon forest land is very sparse consisting mainly of open Eucalyptus and Acacia [a legume], and scrub. Many of the trees
have hollowed out portions in the lower regions filled with mud. Part of the reason for the poor forestation may be due to the
extreme poverty of almost all the soil on the savannas, especially with respect to phosphorus. This is probably due to the activity of Amitermitinae plant smothering species. Cattle become afflicted with
phosphorus deficiency diseases. One head per 20 to 40 acres is usual. People living there have blood below normal in phosphorus content (Taylor, 1949, p111-418). This deficiency may be reinforced by the recent foolish introduction of refined flour (Price, 1950). Settlements are usually confined to rain forests. According to Orr, a concentration of phosphorus pentoxide of about 0.3% in food will
cause brittle bone disease of cattle, a critical range is in the vicinity of 0.5%. 0.9% is optimum for cattle (Orr, 1929). Southern tree
grass analyzes 0.129%, Kangaroo grass 0.122%, and Tussock 0.17% (Orr, 1929). The vegetation in south west Australia is characteristically low in phosphorus (Lambers).

Present day animals are even smaller than animals in the past. They took a sudden drop in size about 45,000 years ago. This was probably due to savanna fires set by the first arrival of men, which fires degraded the fertility of the soil and favored low nutritive C4 such as spinifex grass [Miller] and most likely also as a result of effective hominid hunting as well.
The recent savanna animal population bears a striking resemblance to that found in the Eurasian Eocene. The game is scarce, has small size, and small light skulls. Even the anteaters are smaller than on the other continents [Milewski]. A species of kangaroo grows as large as a man but it is a southern animal. The Emu is a large predatory bird and ranks with the largest of the land animals in Australia. Apparently it has not forced up the size of the herbivores which depend on speed instead of strength for most of them. As a predator, or perhaps more accurately, an omnivore, it obviously has no problem itself with its phosphorus supply. The amphibians include the largest number of species of any other continent. They are all small and devoid of teeth. Snakes are fairly numerous as individuals. They are all small and all predatory. I doubt if large Cretaceous herbivorous dinosaurs could migrate very far across a present day Australian savanna.

The rain forest is small in area. The vegetation is luxuriant and contains many soft woods from the Indo-Malayan and New
Guinean region. The soft wood would seem to imply either an ant check of Neotermes and Coptotermes or a rather efficient poison in the woods. Part of the plush growth is due to the higher phosphorus pentoxide content of the soil, which has a range from 0.02%
to 0.4%. An adequate value would be 0.2%. Its hay ranges from 0.31% to 0.64%. (Orr, 1929). Such an area should support some
fairly large herbivores but the only large predators are crocodiles and Cassowary birds. However, water buffalo live there now, but I don't know whether they are endemic or not. The rain forest may be similar to Eocene or Oligocene. It is conceivable that some savanna areas may prove to resemble early Paleocene.

SOUTH AMERICA

South American rain forest has many resemblances to the Oligocene in Eurasia. The subgenera Noivamyrmex and Labidus of the
Eciton branch of the Dorylenes occur on North, Central, and South American savannas and could be a factor of importance there for termite control (Schneirla, T.C., private communication) similar to the savanna Ponerines in Africa. Amitermitinae are present, but I am not certain of their impact. However the rise of the very potent leaf cutter ants confuses the situation somewhat. As for the rain forest, the Dorylene ants are probably not as potent as the Dorylenes in Africa. They will not attack a lone nasutiform soldier in their path (Beebe 1919, p233). However, they may have less trouble with Neotermes and little with Coptotermes, both of which are present. Dorylenes may have originated there because an archaic form called Cheliomyrmex resembles both Eciton of South America and Anomma of Africa, and may have helped form the defensive characteristics of Nasutiform termites during the Cretaceous. However, in the modern world, Eciton forages above ground (Wheeler, 1913) and so can not possibly be an important check for subterranean termites or possibly even Amitermitinae tube builders. If it evolved by Cretaceous, it was nevertheless not likely to have had much effect on the termite's effects then, other
than to prevent litter removal. However, if underground Dorylenes existed then {and if dorylines existed then they were underground}, it could explain why some South American
dinosaurs remained very large until late in the Cretaceous, including an extremely large sauropod from Argentina (Paul).
Underground Dorylenes then is highly probable in view of the blindness of present day species. Schneirla believes that the Ponerine genera Leptogenus and Termitopone are much more important than Eciton in raiding termites (Schneirla, T.C., private
communication). Armadillos and anteaters make fairly heavy inroads into the termite's ranks in forested regions. Evidently
predation is adequate in the rain forest, for not only do the most numerous species fail to send runways above ground, but a large
number of Formicidae, Myrmecinae, and Ponerinae, as well as numerous collembola and Thysanura inhabit the thick litter horizon (Williams). South American rain forest animals did not become as large as the animals which inhabit Africa. Leaf cutter ants may be one of the reasons. Another may be the transport of unenriched subsoil to the surface by the dominant Macrotermitinae subfamily fungus growers of Africa and Asia, which subsoil then prevents erosion of the fertile topsoil to a considerable extent. I don't have sufficient analyses or
distribution yet that could decide this.

Game is scarce and small on the uplands and usually eats at the edge of creeks at night (Hingston, 1932). The number of amphibian species are
second only to Australia. The high death rate of sheep is attributed to the phosphorus deficiency of British Guiana's coastal
grassland and the interior (Orr,1929 p109). I'm not certain where I would place South American savanna, but it is obvious that it is
no where near African Miocene in fertility. Panama's savanna termites are peculiar in that they are all forest termites (Emerson, 1952). Perhaps Panama would make a good study area.

CONCLUDING REMARKS

The size and circumstances of the vertebrate population of the above continents and islands tends to mirror that of the fossils in the periods suggested, but the small islands all have smaller endemic animals. I suppose this is partly because they are usually reached by birds or floating logs, and have too small an area to support a large enough of a population to evolve rapidly enough to generate large bodied species. Of course very small islands would not be able to support a viable population of very large animals, especially if there were no large predators to help produce and maintain them.

EXPERIMENTS

All the life forms of the Cretaceous and Tertiary have representatives with us today, so that extensive ecological experiments on islands would
be real easy. Perhaps even more valuable would be experiments involving single species to determine their effects on volcanic ash, especially phosphorus and silica. Such experiments could be made in continental areas on small plots protected by screens and might yield perceptible results in a few decades or less. Some could even be made in pots.

Apparently we are making some experiments inadvertently. I think experiments should be tried on a small scale first, and definitely not by alien introductions. But then, anyone who had lived in a state invaded by fire ants might think that, as I did once. Anyone living in an area invaded by termites may come to feel that way also, and probably will if global warming continues.

REFERENCES

Anderson A Lonsdale WM 1990 Herbivory by insects in Australian tropical savannas: a review. Journal of Biogeography 17; 433-444.

Anderson RR Witzke BJ 1994 The terminal Cretaceous Manson impact structure in north-central Iowa: a window into the late Cretaceous history of the eastern margin of the Western Cretaceous Seaway. In: Shurr GW Landvisson GA Hammond RH, eds. Perspectives on the Eastern Margin of the Cretaceous Western Interior Basin. Special Paper 287. Geological Society of America, inc., Boulder Coloado.

Archbald, JD 1982 A Study of Mammalia and Geology Across the Cretaceous-Tertiary Boundary in Garfield County, Montana.. University of California Press, Geologic Sciences Vol. 122, Bekeley, Los Angeles and London.

Malaka SLO 1977 A study of the chemistry and hydraulic conductivity of mound materials and soils from different habitats of some Nigerian termites. Australian Journal of Soil Research
15;87-91.

Malyshev SI 1966 Genesis of the Hymenoptera. Methuen & Co. London

Massry SG 1978 The clinical syndrome of phosphate depletion. In; Massry SG,Ritz E, Rapado A, eds., Homeostasis of Phosphate and Other Minerals, Proceedings of the 3rd International Workshop of Phosphate and Other Minerals. Columbia University Press, NY.